Update field trial testing config for IsolatedPrerender experiment

Bug: 1023482
Change-Id: Ia17371bdc6fd85ab950fb76ef3ce6eb1ab9d5883
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2226314
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Auto-Submit: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774251}

testing/variations/fieldtrial_testing_config.json

@@ -3145,6 +3145,43 @@
             ]
         }
     ],
+    "IsolatedPrerender": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled_1Prefetch_ISPFiltering",
+                    "params": {
+                        "max_srp_prefetches": "1"
+                    },
+                    "enable_features": [
+                        "IsolatePrerenders",
+                        "IsolatePrerendersMustProbeOrigin"
+                    ]
+                },
+                {
+                    "name": "NoPrefetches_CounterFactualControl",
+                    "params": {
+                        "max_srp_prefetches": "0"
+                    },
+                    "enable_features": [
+                        "IsolatePrerenders"
+                    ]
+                },
+                {
+                    "name": "Enabled_1Prefetch",
+                    "params": {
+                        "max_srp_prefetches": "1"
+                    },
+                    "enable_features": [
+                        "IsolatePrerenders"
+                    ]
+                }
+            ]
+        }
+    ],
     "KeepScriptResourceAlive": [
         {
             "platforms": [